SEOUL, Aug 20 (Reuters) - North Korea hopes to harness the power of sport to raise its image on the world stage through international competitions such as the Olympic Games, and to bolster labour output and national defence by improving its citizens' well-being, the head of a North Korean sports delegation said on Wednesday.

In a rare speech by a North Korean official delivered in the rival South, Yang Song Ho told a sports science congress in Incheon, west of Seoul that the North was working to make sport an everyday concern for the masses.

Yang, an assistant professor at Pyongyang's Korea University of Physical Education, is part of a North Korean delegation that arrived in the South on Tuesday to attend buildup events for the Incheon Asian Games, which open on Sept. 19.

North Korea, which is still technically at war with the South after the 1950-53 Korean War ended in a truce, not a peace treaty, is sending 150 athletes to Incheon for the Games.

Leader Kim Jong Un has placed heavy emphasis on sport since coming to power in 2012. He has hosted NBA hall of famer Dennis Rodman at an exhibition match in Pyongyang and invited Japanese politician and former pro-wrestler Antonio Inoki to hold a wrestling event in the isolated country later this month.

"The DPRK (North Korea) has put forward sports as an important project in achieving the prosperity of the country and nation....," Yang said in a copy of the speech to be delivered later in the day.

In addition to fostering world-class athletes, the ultimate goal of sports development in the North was to ensure its citizens became, "comprehensively developed human beings possessed of sound body and sturdy willpower so that they can contribute to labour and national defence..."

Stressing the importance the country placed on sports development, Yang quoted North Korean leader Kim as saying: "We should raise more fiercely the strong wind of conducting sports throughout the country."

North Korea enjoyed a successful London Olympics in 2012, winning four gold medals in judo and weightlifting to finish 20th on the table.

SANCTIONS, FAMINE

North Korea is one of the world's most reclusive and repressive countries and is under heavy UN sanctions related to its nuclear and ballistic missile programmes.

A nationwide famine in the 1990s killed a million North Koreans and the country's fragile economy is smaller than it was 20 years ago, according to independent estimates.

The North's participation in the Asian Games looked in doubt last month when inter-Korean talks to discuss Pyongyang's plan to take part broke down. One of the sticking points was who would foot the bill for the North Korean delegation's stay.

While concerns that the North may not take part at the Games have now receded, relations between the Koreas remain tense.

North Korea fired three short-range rockets into waters east of the peninsula last Thursday, shortly before Pope Francis arrived in Seoul on his first visit to Asia.

The launches preceded the start of U.S.-South Korean military exercises, which Seoul and Washington say are defensive in nature but the North sees as a rehearsal for war.

Yang said the Asian Games provided a chance to further understanding between countries.

"I believe that the Asian Games will be a great opportunity for strengthening friendship and unity... and promoting mutual understanding and respect...," he said. (Additional reporting by James Pearson; Editing by John O'Brien)